To assess the impact of sulfur(S) fertilization on antioxidant capacity of grazing Wumeng semifine wool sheep in copper(Cu) polluted meadow, and explore the control methods of Cu pollution in natural pasture, fertilizer treatment and grazing experiments were carried out in Weining County of the Wumeng Prairie, Guizhou Province, Southwest China. 24 ha Cu-polluted meadows were fenced, and randomly divided into four groups (3 replications/group, 2 ha/replication): 1) control group, no fertilizer; 2) the tested groups, applied ammonium sulfate [(NH4)₂SO₄] (300, 400, and 500 kg/ha for group I, group II, and group III, respectively). A total of 72 healthy Wumeng semi-fine wool sheep (aged one year, 32.8±1.3 kg) were used in this study. All animals were randomly divided into 4 groups (3 replications/group, 6 sheep/replication) and assigned to the tested pastures. The grazing experiment lasted for 60 days. The results showed that the contents of N, Mn, Zn, and S in herbage in fertilized pastures were markedly higher than those in control group (P<0.01). The contents of Cu, Fe, and Se in herbage in fertilized pastures were significantly lower than those in control group (P<0.01). There were no extreme differences among the fertilized pastures (P>0.05). The contents of Mn, Zn, and S in serum and liver in the tested sheep were significantly higher than those in control animals (P<0.01). The contents of Cu, Fe, and Se in serum and liver in the tested sheep were extremely lower than those in control animals (P<0.01). The levels of Hb, RBC, and PCV in blood in the tested sheep, and the activities of serum SOD, GSH-Px, T-AOC, CAT, and Cp in the tested sheep were extremely higher than those in control sheep (P<0.01). The contents of serum MDA in the tested sheep were significantly lower than those in control animals (P<0.01). There were no great differences among the tested groups in physiological and biochemical parameters (P>0.05). The current results indicated that fertilization of (NH4)₂SO₄ not only markedly influenced the mineral contents of herbage, and samples of blood and liver, but also extremely improved antioxidant capacity in grazing animals from fertilized pastures.